Risk factors for failure of continuous positive airway pressure treatment in patients with ostructive sleep apnoea.

David Slouka,Monika Honnerova,Karel Slama,Petr Hosek,Jana Landsmanova,Radek Kucera,Ales Matas

doi:10.5507/bp.2017.056

Abstract

Obstructive sleep apnoea is a potentially serious sleep disorder associated with the risk of cardiovascular disease. It is treated with continuous airway pressure (CPAP) but this is not always successful. Unsuccessful cases should be treated by bilevel positive airway pressure (BiPAP). The aim of this study was to determine whether common respiratory parameters and/or body mass index (BMI) can be used to predict the probability CPAP failure and hence start such patients on BiPAP from the outset. A sample of patients treated by CPAP for OSAS was evaluated a retrospective cohort study. The data measured in sleep monitoring of the successfully treated group and of the group where CPAP had failed were compared. Subsequently, the predictive abilities of BMI, Apnoea Index (AI), Apnoea-Hypopnea Index (AHI), percentage of sleep time in less than 90% oxygen saturation (T90), average oxygen saturation over the duration of sleep (SaO2) and average desaturation per hour of sleep (ODI) were assessed with respect to CPAP failure, both individually and in combination. A sample of 479 patients was included in the study. All of the recorded variables except AI were significantly associated with failure of CPAP and their ability to predict the failure ranged from poor to moderate. Since there was significant correlation among all the variables measured a two-variable prediction model combining T90 and BMI produced no significant improvement in the quality of CPAP failure prediction. BMI was a significant predictor of CPAP failure although it was slightly less predictive than T90. The set of monitored variables included in our study does not allow for CPAP failure to be predicted with clinically relevant reliability.

Highlights

The obstructive sleep apnea syndrome (OSAS) is a potentially serious sleep disorder characterized by repetitive pauses in respiration or periods of reduced breathing during the sleep
With the exception of Apnoea Index (AI) (P=0.1785), all of the quantitative variables were significantly associated with the success/failure of continuous positive airway pressure (CPAP) (Fig. 1, Apnoea-Hypopnea Index (AHI): P=0.0172, than 90% oxygen saturation (T90): P
Even though our results showed that BMI, as well as AHI, ODI, T90 and SaO2 were significant risk factors for CPAP failure, the Receiver Operating Characteristic (ROC) analysis suggests that none of these variables alone or in combination can be used for the predicting CPAP failure with clinically relevant reliability

Summary

Introduction

The obstructive sleep apnea syndrome (OSAS) is a potentially serious sleep disorder characterized by repetitive pauses in respiration or periods of reduced breathing during the sleep. OSAS increases overall morbidity and mortality and it is associated with a triple increased risk of cardiovascular disease[3,4] In patients with this condition, there is a greater prevalence of obesity than in the general population, according to available studies, in 40-70% of patients with OSAS (ref.5,6), and considered to be one of the respiratory complications of obesity. This must be replaced by bilevel positive airway pressure therapy (BiPAP) (ref.[13]). Both devices operate on the same principle. Obstructive sleep apnoea is a potentially serious sleep disorder associated with the risk of cardiovascular disease It is treated with continuous airway pressure (CPAP) but this is not always successful. The set of monitored variables included in our study does not allow for CPAP failure to be predicted with clinically relevant reliability

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Conclusion